<template>
  <div>
      <ul>
          <li v-for="(item, ind) in arr" :key="item">
              <span>{{ item }}</span>
              <button @click="del(ind)">删除</button>
          </li>
      </ul>
      <button @click="add">生成</button>
  </div>
</template>

<script>
export default {
    data () {
        return {
            arr: [5, 7, 1]
        }
    },
    methods: {
        add(){
            this.arr.push(Math.floor(Math.random() * 20));
        },
        del(index){
            this.arr.splice(index,1)
        }
    }
}
</script>

<style>

</style>